As the World Becomes Urban, Cities Are Key to Climate
Protection
Most of the world’s energy use and carbon emissions come from cities.
By improving efficiency, transportation, and urban planning, the
world’s biggest cities could turn from polluters into a vital part of the
solution to climate change - and better places to live.
When London introduced its congestion charge in 2003, motorists and local
businesses feared for the worst - the same congestion, but higher costs and fewer
customers. After half a year, traffic in central London was down by 30 percent with
little impact on businesses. Two years later, building on this success, London Mayor
Ken Livingston invited mayors and representatives from the 40 biggest cities in the
world to discuss what else they could drive down carbon emissions and pollution. The
C40 Large Cities Climate Summit was born - and none too soon.
According to the United Nations, 2008 is the first year in which over half of the
world's population - roughly 3.3 billion people - lives in cities. With the growth of
large cities in Africa and Asia, the number of urbanites could climb to 5 billion by
2030. As cities grow, so does their impact on the global environment.
"Cities are responsible for the vast majority of the world's energy use and
greenhouse gas emissions," says Janet Sawin, director of the Energy and Climate
Program at the Worldwatch Institute. For instance, Indian cities, where a third of the
country's 1.1 billion people live, consume 87 percent of India's electricity - most of
which is produced by coal-fired power plants that produce massive amounts of
carbon dioxide. Ulaanbaatar (Mongolia) has similar problem and the whole area is
polluted.
Cutting energy use
Cities will always need lots of energy for light, heat, importing food, and
transportation; they just need to find more efficient ways of doing it. During the
latest C40 Large Cities Climate Summit in New York, five international banks
committed to five billion dollars in loans to former U.S. President Bill Clinton's green
building initiative, which will spend the money on energy efficiency projects in 15 of
the world's biggest cities, including London, Sao Paolo, Mumbai, Tokyo, and Berlin.
Avoiding old mistakes
Mexico City and Bogotá, Colombia have made big improvements to local transport,
such as replacing old taxis (India has done it too) and introducing efficient mass
transport systems. Traffic runs freer now and commute times have dropped, as well
the cities' overall pollution and emissions.
Another strategy is city planning that prevents pollution from vehicles and transport
by reversing urban sprawl and improving public transportation. This could help
reduce reliance on cars, particularly in U.S. cities.
Incorporating clean, renewable energy is another concept. Ninety-nine percent of all
homes in Rizhao, China - a coastal city of nearly three million people - use solar
water heaters, while the local government has installed solar panels to power street
and traffic lights. The Hammarby Sjöstad district in Stockholm uses residential waste
to produce biogas, which is then used to heat homes and power local trains.
C40 Large Cities Climate Summit: The C40 Large Cities Climate Summits are
designed to help mayors deliver action in combating climate change. Each summit
brings together an unprecedented number of mayors from major cities, their senior
staff and business leaders. Through a comprehensive programme of interactive
sessions, delegates can share best practices and identify collaborative projects all
aimed at tackling climate change.
The first summit was held in London in 2005 and the second summit took place from
14 May - 21 May 2007 in New York City. The next city to host the C40 summit was
Seoul. On May 18 2009, 80 leading cities around the world met in Seoul to discuss
climate concerns under the theme of 'Cities' Achievements and Challenges in the
Fight against Climate Change. This third summit of the C40 Cities Climate Leadership
Group, provided a key opportunity to review progress that cities have made in
reducing greenhouse gas emissions and assess future challenges.
The World's Ten Biggest Metropolitan Areas
1. Tokyo, Japan
Metropolitan area: 34 million people
City: 12.5 million people
Tokyo is by far the largest urban region in the world. Despite its size and
complexity, Tokyo has a very efficient public transportation, which accounts for
almost 80 percent of all daily journeys in Tokyo.
Urban Detail:
Tokyo Bay has been gradually filled up to create more space for housing and
offices. Odaiba, an island entirely created out of waste material, became one of
Tokyo’s most interesting tourist spots with futuristic architecture, shopping, and
entertainment centers. (Photo: Miki Yokoyama)
2. Seoul, South Korea
Metropolitan area: 23.9 million people
City: 10.3 million people
Seoul has grown rapidly since the Korean War (1950-53). Today, nearly half of the
country’s population lives in Seoul and its surrounding area. In recent years, Seoul
modernized the city’s transportation system and created more public green spaces.
Urban Detail:
Foreign direct investment in Seoul has dropped about 20 percent since 2000. Many
companies dread South Korea’s restrictive regulations on foreign investment, its
government monopolies, and strict immigration rules. (Photo: Reuters)
3
Mexico City, Mexico
Metropolitan area: 22 million people
City: 8.7 million people
Mexico City is ten times the size it was in 1940. Now with about 22 million
people in the metro area, the Mexican capital generates almost a quarter of
the country's wealth. However, with a low population growth of 0.99 percent,
the number of people in retirement is expected to rise rapidly in the next
decades.
Urban Detail:
Security, air pollution, and traffic congestion are prime concerns in Mexico
City – problems that result from poor resource management and unstructured
growth. (Photo: Reuters)
4. New York, United States
Metropolitan area: 21.9 million people
City: 8.2 million people
New York City, especially Manhattan, is a role model for balancing dense
development with good public transport and access to open spaces. Different in
many regards, New York City is the only U.S. city where most households do not own
a car.
Urban Detail:
New York City has been a major point of entry since the first immigrants came to the
United States. Over 170 languages are spoken there today. No single nationality or
ethnicity dominates the city’s exceptionally cultural diverse population. (Photo:
Reuters)
5. Mumbai, India
Metropolitan area: 21 million people
City: 13 million people
Mumbai – known as Bombay until the name was officially changed in 1995 – is the
most densely populated city in the world. Through high birth rates and a perpetual
influx of migrants, Mumbai’s population is expected to grow by one fifth in the next
ten years.
Urban Detail:
Over half of the city’s population is still living in slums. Poor infrastructure and
widespread poverty make it very difficult to meet the demands of an ever-growing
population. (Photo: Reuters)
6. Sao Paulo, Brazil
Metropolitan area: 19.6 million people
City: 11 million people
Sao Paulo, the sixth-largest metropolis in the world. It is Brazil’s richest city and
the most important financial center in Latin America. Poverty and crime,
however, remain a problem. An average of 6,000 people is murdered annually.
Urban Detail:
With more than 66 percent of its population under twenty years and many
immigrants, Sao Paulo is a very young and ethnically diverse city. (Photo:
Shutterstock)
7. Los Angeles, United States
Metropolitan area: 17.9 million people
City: 3.9 million people
Los Angeles is the second biggest city in the United States by land size. An extensive
grid of freeways, boulevards, and smaller neighborhood roads spans the city.
Urban Detail:
Los Angeles is home to the largest Mexican, Guatemalan, and Korean population
outside of those countries. Almost 40 percent of the city’s population was born
outside the United States. (Photo: Reuters)
8. Shanghai, China
Metropolitan area: 17.8 million people
City: 9.8 million people
With China’s growing gross domestic product and economic strength, Shanghai has
become the financial and commercial center of the country with one of the world’s
busiest ports and the world’s most extensive bus systems with nearly one thousand
lines.
Urban Detail:
Shanghai is a relatively homogenous city, with only 0.7 percent of its population born
outside of China. Shanghai’s population growth is mainly powered by inward
migration from rural areas, also called the "floating population." (Photo: Reuters)
9. Jakarta, Indonesia
Metropolitan area: 15 million people
City: 9.3 Million people
Jakarta had to suffer major setbacks in the past decade due to the economy crisis in
1998 and natural disasters like floods and earthquakes. Since 2005, Jakarta has
made an economic recovery, boosting Indonesia’s economy to a robust growth rate
of 6 percent.
Urban Detail:
Many parts of Jakarta’s biggest river, the Ciliwung, are heavily polluted and clogged
with garbage, strongly affecting the city’s environment and its surroundings and
causing serious damage to the coastal ecosystem. (Photo: Reuters)
10. Moscow, Russia
Metropolitan area: 13.4 million people
City: 11.3 million people
For the second time in a row, Moscow was named the most expensive city for
expatriates in 2007. With more passengers than New York City and London
combined, Moscow has the world’s busiest metro system serving more than nine
million people a day.
Urban Detail:
Despite Russia’s capital getting richer, its population has been declining due to low
birth rates and short life expectancy. (Photo: Reuters)
Sea Change: A Carbon Sink on the Brink
Oceans are one of the world’s most important carbon sinks. They have
helped to keep global warming at bay, but as they turn more acidic,
scientists realize that global warming is not the only problem caused by
CO2.
Drop a piece of chalk in a glass of vinegar, watch it dissolve, and you'll get an idea of
what unchecked carbon dioxide emissions might do to marine life. In fact, scientists
now believe that marine species and ecosystems could be among the first casualties
of man-made carbon dioxide emissions.
If not for the oceans, global warming would have been a lot more pronounced by
now. About a third of all man-made carbon dioxide emissions have ended up in the
Earth's oceans, which are, along with rainforests, the most important carbon sink on
the planet. But this service has a price: the more CO2 the oceans take up, the more
acidic they become.
When carbon dioxide combines with water, carbonic acid is formed and hydrogen
ions are released - a chemical process that increases the ocean's acidity. As a result
of increasing CO2 concentrations, ocean surfaces are now 30-percent more acidic
than they were before the Industrial Revolution, and probably more acidic than
anytime in the last 20 million years.
The acid test
If carbon emissions grow unchecked, the UN's Intergovernmental Panel on Climate
Change (IPCC) says that oceanic acidity could increase further by up to 150 percent
from pre-industrial levels until the end of this century.
This spells trouble for small marine species - mollusks, crustaceans, algae, and
plankton - that build their skeletons or shells out of calcium carbonate. Lower pH
levels, a measurement for acidity, would disrupt their growth, or worse, dissolve the
shells right off their back. And since these organisms provide the basis of marine
food chains, their migration or disappearance could have devastating impacts on
larger species.
If, for example, the tiny, swimming sea snails known as pteropods vanish, even
whales would suffer. "Pteropods are prey for many species from salmon to whales,"
says Scott Doney, a senior scientist at the U.S.-based Woods Hole Oceanographic
Institution. "Their demise will likely have significant consequences."
Scientists now call ocean acidification "the other half of the CO2 problem" - not the
one heating up our atmosphere, but rather the one unfolding below the waves.
Researchers fear that increasing acidification could destroy what is left of the world's
coral reefs and the very base of marine food chains by the end of this century.
Coral grief
Combined with over-fishing and pollution, acidification threatens the coral reefs all
over the world. In many reefs, scientists have already observed the phenomena of
"coral bleaching." This occurs when colorful, symbiotic algae cannot survive on their
coral hosts because the water is too warm, polluted, or acidic. Once the algae goes,
the coral's white skeleton beneath is exposed.
Acidification also disrupts coral calcification, the process that creates reefs. In a
December 2007 issue of Science, a team of researchers projected that by century's
end, most waters could be too acidic for most coral to grow. If the IPCC's more dire
scenarios for CO2 concentrations and warming come to pass, few existing coral reefs
will survive by end of the century.
"The loss of tropical corals would have profound negative impacts, because they
support some of the most diverse and rich ecosystems on the planet," says Scott
Doney.
The decline of shallow-water reefs would affect millions of people, since these natural
structures are essential to supporting local fisheries and tourism, and provide coastal
protection from storms. According to the Nature Conservancy, reefs produce up to
375 billion U.S. dollars in "goods and services" each year.
Such figures are bound to get the attention of policymakers. According to Carol
Turley, a scientist at the Plymouth Marine Laboratory in Britain and lead author of
the most-recent IPCC assessment, awareness of the acidification issue has increased
"hugely" over the last five years.